From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751385Ab3KKVI1 (ORCPT ); Mon, 11 Nov 2013 16:08:27 -0500 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.226]:18896 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750961Ab3KKVIU (ORCPT ); Mon, 11 Nov 2013 16:08:20 -0500 Date: Mon, 11 Nov 2013 16:08:10 -0500 From: Steven Rostedt To: LKML Cc: Arnaldo Carvalho de Melo , Jiri Olsa , Ingo Molnar , Namhyung Kim , Frederic Weisbecker Subject: [PATCH] tools lib traceevent: Add direct access to dynamic arrays Message-ID: <20131111160810.0ba9df7d@gandalf.local.home> X-Mailer: Claws Mail 3.9.2 (GTK+ 2.24.20; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-RR-Connecting-IP: 107.14.168.118:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jiri Olsa was writing a plugin for the cfg80211_tx_mlme_mgmt trace event, and was not able to get the implemented function working. The event's print fmt looks like: "netdev:%s(%d), ftype:0x%.2x", REC->name, REC->ifindex, __le16_to_cpup((__le16 *)__get_dynamic_array(frame)) As there's no helper function for __le16_to_cpup(), Jiri was creating one with a plugin. But unfortunately, it would not work even though he set up the plugin correctly. The problem is that the function parameters do not handle the helper function "__get_dynamic_array()", and that passes in a NULL pointer. Adding PRINT_DYNAMIC_ARRAY direct support to eval_num_arg() allows the use of __get_dynamic_array() in function parameters. Reported-by: Jiri Olsa Signed-off-by: Steven Rostedt --- tools/lib/traceevent/event-parse.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c index 8f450ad..0362d57 100644 --- a/tools/lib/traceevent/event-parse.c +++ b/tools/lib/traceevent/event-parse.c @@ -3435,6 +3435,19 @@ eval_num_arg(void *data, int size, struct event_format *event, struct print_arg goto out_warning_op; } break; + case PRINT_DYNAMIC_ARRAY: + /* Without [], we pass the address to the dynamic data */ + offset = pevent_read_number(pevent, + data + arg->dynarray.field->offset, + arg->dynarray.field->size); + /* + * The actual length of the dynamic array is stored + * in the top half of the field, and the offset + * is in the bottom half of the 32 bit field. + */ + offset &= 0xffff; + val = (unsigned long long)(data + offset); + break; default: /* not sure what to do there */ return 0; } -- 1.8.4.rc3